EP0762008A1 - Brake calipher having earth connection and holder for warning contact plug - Google Patents

Abstract

The arrangement consists of a housing (2,3,4,5) with two brake pads (7,8) and a warning system which indicates wear of the friction lining of at least one of the brake pads. An electric cable (19) runs from at least one of the brake pads via a plug to an indicator on the dashboard. The brake saddle (1) incorporates a mounting bracket (25) for the warning contact plug. The saddle has at least one earth connection (29) which is part of the mounting bracket (25) for the plug. The bracket (25) is stamped out of sheet metal and bent into shape. The earth connection (29) extends at right angles from the base of the bracket.

Description

The invention relates to a brake caliper for partial lining disc brakes, in particular for motor vehicles, with a friction lining warning device and a holder for a warning contact plug according to the preamble of claim 1.

A brake caliper for brake pad disc brakes with a housing, in the shaft of which two brake shoes are held and guided by two pins and braced against the retaining pins by a spring without rattling, is known, for example, from German patent application DE 39 17 125. The brake shoes are provided with a friction lining warning device that indicates the wear of the friction linings via a wear sensor arranged in the brake linings, an electrical conductor and a warning contact plug on a device, so that these can be replaced in good time and brake failure can be avoided. In order to prevent damage to the electrical conductor by the wheel rim or the disc brake if the warning cable hangs loosely between the brake and the rim, a holder for the electrical conductor is provided on the brake caliper, through which the warning cable is held and guided.

German patent application DE 40 27 944 discloses, in addition to guiding the electrical conductor, a holding bracket for the warning contact plug which is detachably fastened to the brake caliper, the holding bracket simultaneously serving to receive and hold a brake hose.

With these brake calipers, the electrical conductor of the friction lining warning device consists of two individual insulated warning wires that lead from the wear sensor to the display device. Two different measuring methods for lining wear are known. On the one hand, when the friction lining wears, an electrical cable connecting the two warning wires and located in the sensor is severed from the brake disc, as a result of which a current flow is interrupted and an electrical display is triggered. On the other hand, the brake disc creates a conductive connection between two ground cables that are insulated from each other when the lining is worn, whereby a circuit is closed and the display device is activated.

The brake disc itself is not connected to the mass, since it is attached to a wheel suspension, which is mounted elastically via rubber bearings and electrically insulated from the mass circuit of a vehicle. For this reason, the latter measuring method frequently results in malfunctions in the display of the wear of the lining, in particular in a delayed display.

In order to prevent this malfunction of the lining wear indicator device, it has been proposed to connect the brake disc to the ground circuit of the vehicle via a plug contact located on the wheel carrier. However, this solution is very expensive because it increases the number of individual parts of a motor vehicle and furthermore requires a complex axle construction for guiding and holding the ground cable.

It is therefore the object of the present invention to connect the brake disc of a motor vehicle brake to the earth circuit of the vehicle in a simple and inexpensive manner in an electrically conductive manner for the safe functioning of the friction lining warning device.

This object is achieved by the features listed in the characterizing part of claim 1.

According to the invention, a ground connection is provided on a brake caliper for partial lining disc brakes, the brake caliper essentially comprising a housing, a holder for at least one warning contact plug and two brake shoes guided on retaining pins, which have a sensor of a warning device for indicating the lining wear in at least one of the friction linings. The ground connection, which can be easily connected to the ground circuit of a motor vehicle, advantageously provides for the ground connection of the brake disc via the brake caliper, a steering knuckle and a wheel bearing. In this way, a reliable function of the friction lining warning device is guaranteed according to the invention. Another advantage of this construction is that instead of a warning cable with two electrical conductors, only a ground cable can be used, so that when the brake pad wears, a circuit is closed and the display device is activated via the contact of the brake disc with the ground cable. Furthermore, the disadvantage of a complex and expensive axle construction for guiding and holding the ground cable in the event of a ground contact on the wheel carrier is avoided.

In the present invention, the ground connection is advantageously formed on the holder for the warning contact plug. This advantageously prevents costly machining of the saddle housing and an increase in the number of parts. It is particularly advantageous that the same holder can also be used as a mass-produced part for brake calipers in which a ground fault of the brake disc is not necessary or possible for the friction lining warning device, for example in the case of brake discs made of carbon fiber materials. The ground connection is then not connected to the ground circuit of the vehicle and the holder is used only for fastening at least the warning contact plug.

In the preferred embodiment of the invention, an inexpensive to manufacture, in particular stamped and bent holding plate is provided as a holder for the warning contact plug. The ground connection is preferably pulled in one piece from the sheet, but can also be soldered as a separate part to the holding plate or connected in an electrically conductive manner in another way.

The ground connection is advantageously arranged in an easily accessible manner on the upper part of a base section. The holding plate further comprises a plane section, which preferably extends at right angles from the base section and is provided with a bore for fastening the holding plate to the saddle housing by means of a screw. A U-shaped holding section is formed from part of the base section, in which the warning contact plug is held securely in a non-positive and positive manner. Another section, which preferably extends at right angles from the base section in the opposite direction to the fastening section, is provided with at least one semicircular opening for holding a further cable, in particular an ABS cable. With appropriate dimensioning of the holding plate, however, it is also possible to provide a plurality of openings for holding further cables or hoses on this holding section. The particular advantage of the design of the retaining plate according to the invention is that that the individual cables and hoses are not obstructed and are arranged in a particularly clear manner.

In order to avoid machining the housing, for example by making a threaded blind hole for the fastening screw of the retaining plate, in another embodiment of the brake caliper, a simple and inexpensive wire clip, which is preferably bent from spring wire, is provided as a warning contact plug holder.

In a particularly expedient embodiment of this spring wire clip, the ground connection according to the invention is formed by a plurality of circular wire loops one behind the other. The spring wire clip further comprises a semicircular holding section for the warning contact plug and at least one further, likewise semicircular, holding section for the ABS cable or other cables or hoses. The wire clip advantageously has at least one loop and a projection for fastening it to existing heels of the saddle housing.

In a further embodiment of the brake caliper, the ground connection according to the present invention is formed on at least one of the pad retaining pins, but preferably on both.

The ground connection is provided through a hole made at the inner end of at least one retaining pin. This type of production is particularly simple and inexpensive because the respective bore can be made before the lining retaining pins are installed. If the diameter of the retaining pins is not large enough for a common ground connection due to the dimensioning of the brake, the respective end of the retaining pins can be provided with a corresponding shoulder with a larger diameter.

If the earth connection is on the pad retaining pins, a simple bracket stamped from sheet metal and bent can be used as a bracket for the warning contact plug. The bracket comprises a fastening section, a U-shaped warning contact plug holding section and at least one further section for holding further cables and hoses.

Instead of this bracket, a spanner-shaped retaining clip can also be provided according to the invention, which is preferably made of plastic at low cost. The holding clip comprises a fastening section and a holding section for the warning contact plug, the fastening section advantageously being clamped onto a location provided behind the holding pin shoulder with the larger diameter on one of the two lining holding pins and being held securely there.

Fig. 1

eine Draufsicht auf eine bevorzugte Ausführungsform eines erfindungsgemäßen Bremssattels mit einem an einem Halteblech angeordneten Masseanschluß,

Fig.2

den in Fig. 1 dargestellten Bremssattel in einer Seitenansicht,

Fig. 3

eine perspektivische Darstellung des in den Fig. 1 und 2 gezeigten Halteblechs,

Fig. 4

eine Draufsicht auf eine andere Ausführungsform eines Bremssattels mit einem in einem Drahtclip ausgebildeten Masseanschluß,

Fig. 5

den in Fig. 4 dargestellten Bremssattel in einer Seienansicht,

Fig. 6

eine perspektivische Darstellung des in den Fig. 4 und 5 gezeigten Drahtclips,

Fig. 7

eine Draufsicht auf eine weitere Ausführungsform eines Bremssattels mit einem Haltewinkel und an Belaghaltestiften befindlichen Masseanschlüssen,

Fig.8

den in Fig. 7 dargestellten Bremssattel in einer Seitenansicht,

Fig. 9

eine Draufsicht auf eine weitere Ausführungsform eines Bremssattels mit einem Halteclip und an Belaghaltestiften befindlichen Masseanschlüssen,

Fig.10

einen Teil des in Fig. 9 dargestellten Bremssattels in einer Seitenansicht und

Fig.11

eine perspektivische Darstellung des in den Fig. 9 und 10 gezeigten Halteclips mit einem daran befestigten Warnkontaktstecker.

Various embodiments of the present invention are explained in more detail below with reference to the drawings. Show it

Fig. 1

2 shows a plan view of a preferred embodiment of a brake caliper according to the invention with a ground connection arranged on a holding plate,

Fig. 2

1 in a side view,

Fig. 3

2 shows a perspective illustration of the holding plate shown in FIGS. 1 and 2,

Fig. 4

3 shows a plan view of another embodiment of a brake caliper with a ground connection formed in a wire clip,

Fig. 5

4 in a side view,

Fig. 6

3 shows a perspective illustration of the wire clip shown in FIGS. 4 and 5,

Fig. 7

1 shows a plan view of a further embodiment of a brake caliper with a holding bracket and ground connections located on pad holding pins,

Fig. 8

7 in a side view,

Fig. 9

3 shows a plan view of a further embodiment of a brake caliper with a holding clip and ground connections located on pad holding pins,

Fig. 10

a part of the caliper shown in Fig. 9 in a side view

Fig. 11

a perspective view of the holding clip shown in FIGS. 9 and 10 with an attached warning contact plug.

1 and 2 show a preferred embodiment of a brake caliper 1 according to the invention for partial lining disc brakes in a top and side view. The brake caliper 1 has a housing 2 with an outer leg 3 and two bridge sections 4, 5, which delimit a bridge shaft 6. In the shaft 6, two brake shoes 7, 8 are arranged, each consisting of a carrier plate 9, 10 and a friction lining 11, 12 and are guided via retaining pins 13, 14. When braking, at least the lining 12 of the inner brake shoe 8 is pressed directly against a brake disc, not shown, via a hydraulic cylinder 15 is between the brake shoes 7, 8. A spring 16 braces the brake shoes 7, 8 against the pins 13, 14 in order to dampen a noise that occurs during the braking process due to the relative movement between the shoes 7, 8 and the holding pins 13, 14.

A lining wear sensor 17 of a friction lining warning device 18 is preferably located in the inner friction lining 12, an electrical conductor 19 leading from the sensor 17 to a warning contact plug 20, which is connected to a display device, not shown, on which the degree of wear of the friction lining 12 can be read . With increasing wear of the friction lining 12, the brake shoe 8 moves towards the brake disc, which is why the electrical conductor or warning wire 19 must be dimensioned long enough to be able to follow this movement. So that the warning wire 19 does not reach the brake disc or a wheel rim (not shown) and can be damaged or destroyed there, it is guided through an eyelet 21 which is fastened on a shoulder 22 of the housing 2 by means of a screw 23.

The warning contact plug 20 of the friction lining warning device 18 is inserted into a U-shaped section 24 of a holder formed as a holding plate 25 and held there, the holder 25 being fastened by a screw 26 to a shoulder 27 of the housing 2 provided for this purpose. According to the invention, a ground connection 29 is provided on an upper section 28 of the holding plate 25.

The brake caliper 1 is fastened via the housing 2 to a steering knuckle, not shown, of a motor vehicle, so that a ground connection between the brake caliper 1 and the brake disc takes place via a wheel bearing, also not shown. The ground connection of these parts with the vehicle body is not given because the wheel suspension over Rubber bearing is elastically and electrically insulated in the steering knuckle. For this reason, according to the invention, the brake disc is supplied with ground via the ground connection 29 of the holding plate 25, the brake caliper 1 and the wheel bearing.

When the brake lining 12 wears, the lining wear sensor 17 comes into direct contact with the brake disc, as a result of which a circuit is closed and the wear of the friction lining 12 can be read on the display device. If the brake disc is connected to the ground of the motor vehicle circuit via the ground connection 29, the warning wire 19 of the friction lining warning device 18 can consist in a particularly advantageous manner of only one ground line.

The exact shape of the holding plate 25 according to the invention is shown in perspective in FIG. 3. The holding plate 25, which is expediently stamped out of sheet metal and then bent, comprises the holding section 24 for the warning contact plug 20, the upper section 28 with a ground connection 29 preferably drawn in one piece therefrom, a base section 30, a fastening section 31 with a bore 32 and a further holding section 33 the end of which is a semicircular opening 34. The holding plate 25 is fastened by means of the screw 26 which extends through the opening 32 to the housing shoulder 27 provided for this purpose. The fastening section 31, which extends at right angles to the base section 30 to the rear, is flat and has two shoulders 35, behind which its width is reduced, in order to reduce the contact surface. The section 24 is bent upward from a part of the base section 30 and, due to its round shape, serves to hold the warning contact plug 20 securely in a force-fitting and form-fitting manner. The holding section 33, which also extends at right angles from the base section 30 in the opposite direction to the fastening section 31, can be used through its opening 34 pick up an ABS cable or other cable. Here, the holding sections 24 and 33 are arranged on the holding plate 25 in such a way that the parts to be held are held optimally. As a continuation of this embodiment of the holding plate 25, it is conceivable to provide further openings (not shown) for receiving additional cables or hoses on the sides of section 33.

4 and 5, analogous to FIGS. 1 and 2, a top and a side view of another embodiment of the brake caliper 1 is shown. A wire clip 36, which is clamped behind a projection 37 of the cylinder 15 and has a ground connection 38 according to the invention, serves as a holder for the warning contact plug 20. By clamping the wire clip 36, it is advantageously possible to dispense with machining the housing, such as, for example, making a threaded blind hole for the screw 26.

The wire clip 36, which is preferably bent from spring wire, is shown in perspective in FIG. 6. In addition to the ground connection 38 formed by a plurality of circular loops, the spring wire clip 36 has a semicircular holding section 39 for the warning contact plug 20 and a further semicircular holding section 40 for an ABS cable (not shown), the sections 39, 40 in turn being arranged on the spring wire clip 36 that an optimal recording and mounting of the connector 20 or the ABS cable is made possible. A loop 41 and a projection 42 engaging behind the housing 2 are provided for attachment to the projection 37 or to the saddle housing 2. The individual sections 38, 39, 40, 41 and 42 are connected to one another via webs 43, 44, so that the wire clip 36 can be bent from a single piece of spring wire.

A top view and a side view of a further embodiment of a brake caliper 1 is shown in FIGS. 7 and 8. According to the invention, in contrast to the previous embodiments, at least one earth connection 45, 46 is provided on the pad retaining pins 13, 14, the earth connection 45, 46 preferably being produced by drilling the inner ends of the retaining pins 13, 14. Since the holding pins 13, 14 shown in FIGS. 7 and 8 are too small in diameter, they each have a shoulder with a larger diameter at their inner ends, in which the mass connections 45, 46 can be introduced with a sufficient residual wall thickness. A bracket 47 for the warning contact plug 20 is fastened to the housing shoulder 27 by means of a screw 48 via a section 49. By providing the ground connections 45, 46 on the holding pins 13 and 14, the mounting bracket 47 no longer has its own ground connection, but is provided, as above, with a holding section 50 for the warning contact plug 20 and a holding section 51 with an opening 52 for holding an ABS cable .

A further embodiment of the brake caliper 1 is shown in FIGS. 9 and 10 in a top and side view. The ground connections 45, 46 are attached analogously to the previous embodiment on shoulders of the holding pins 13, 14, which have a larger diameter than the holding pins 13, 14. In this embodiment, however, in contrast to the previous one between these paragraphs and the fastening of the holding pins 13, 14 to the saddle housing 2, a holding pin section to which a holding clip 53 is fastened remains free.

This holding key 53, shown in perspective in FIG. 11 and expediently made of plastic, comprises a section 54 for fastening with one of the holding pins 13, 14 and a section 55 for receiving of the warning contact plug 20, the two sections 54, 55 being connected to one another by a web 56.

Reference list

1

Brake caliper

2nd

casing

3rd

Housing leg

4th

Bridge section

5

Bridge section

6

Bridge shaft

7

Brake shoe

8th

Brake shoe

9

Carrier plate

10th

Carrier plate

11

Friction lining

12th

Friction lining

13

Retaining pin

14

Retaining pin

15

Hydraulic cylinder

16

feather

17th

Pad wear sensor

18th

Friction lining warning device

19th

Warning wire

20th

Warning contact plug

21

eyelet

22

Housing heel

23

screw

24th

Holding section

25th

Bracket

26

screw

27

Housing heel

28

Bracket section

29

Ground connection

30th

Base section

31

Fastening section

32

drilling

33

Holding section

34

opening

35

paragraph

36

Spring wire clip

37

head Start

38

Ground connection

39

Holding section

40

Holding section

41

loop

42

head Start

43

web

44

web

45

Ground connection

46

Ground connection

47

Bracket

48

screw

49

Fastening section

50

Holding section

51

Holding section

52

opening

53

Holding clip

54

Fastening section

55

Holding section

56

web

Claims (10)

Brake caliper for partial brake disc brakes, in particular for motor vehicles, with a housing (2, 3, 4, 5), two brake shoes (7, 8) and a friction lining warning device (18) which indicate wear of a friction lining (11, 12) on at least one the brake shoe (7, 8) indicates and has at least one electrical conductor (19) guided on the brake caliper (1), which leads from the at least one brake shoe (7, 8) via a warning contact plug (20) to a display device, the brake caliper ( 1) comprises a holder (25, 36, 47, 53) for at least the warning contact plug (20), characterized in that the brake caliper (1) has at least one earth connection (29, 38, 45, 46). Brake caliper according to claim 1, characterized in that the earth connection (29, 38) is formed on the holder (25, 36) for the warning contact plug (20). Brake caliper according to claim 1 and 2, characterized in that the holder is designed as a stamped and bent holding plate (25). Brake caliper according to claim 3, characterized in that the holding plate (25) has a base section (30) with a ground connection (29) arranged on its upper section (28), a fastening section (31) preferably extending at right angles to the base section (30) and having a Bore (32), from a part of the base section (30) U-shaped bent section (24) for the warning contact plug (20) and a holding section (33) which extends preferably at right angles to the base section (30) in the opposite direction to the fastening section (31) and which has at least one semicircular opening (34) for holding a cable, in particular an ABS cable. Brake caliper according to claim 1 and 2, characterized in that the holder is designed as a bent spring wire clip (36). Brake caliper according to claim 5, characterized in that the spring wire clip (36) has a ground connection (38) formed by a plurality of circular loops, a semicircular holding section (39) for the warning contact plug (20), at least one further semicircular holding section (40), in particular for one ABS cable, as well as a semicircular loop (41) and a projection (42) for fastening the wire clip (36) to the brake caliper (1), the individual sections (38, 39, 40, 41, 42) by webs (43 , 44) are interconnected. Brake caliper according to claim 1, characterized in that the earth connection (45, 46) is formed on at least one of the pad retaining pins (13, 14). Brake caliper according to claims 1 and 7, characterized in that the earth connection (45, 46) is made by means of a bore in at least one of the retaining pins (13, 14). Brake caliper according to Claim 8, characterized in that a holding bracket (47) stamped and bent from sheet metal is provided as a holder for the warning contact plug (20) and has a fastening section (49), a U-shaped bent section (50) for the warning contact plug (20) and a further section (51) with at least one semicircular opening (52), in particular for holding an ABS cable. Brake caliper according to claim 8, characterized in that a spanner-shaped holding clip (53) with a fastening section (54) and a holding section (55) is provided as a holder for the warning contact plug (20), the fastening section (54) being attached to one of the lining holding pins (13 , 14) is inserted and the holding section (55) is used to hold the warning contact plug (20).

Images